Precipitator collecting electrode



Nov. 13, 1951 w. E. MACK PRECIPITATOR COLLECTING ELECTRODE Filed July14, 1948 INVENTOR WAYNE E.MACK J Patented Nov. 13, 1951 PRECIPITATORCOLLECTING ELECTRODE Wayne E. Mack, Martins Ferry, Ohio, assignor toWheeling Steel Corporation, Wheeling, W. Va., a corporation of DelawareApplication July 14, 1948, Serial No. 38,597

6 Claims. 1

This invention relates to precipitator collecting electrodes. It has todo with electrodes for collecting solid particles removed from gases inelectrical precipitators.

In copending application Serial No. 38,638, filed of even date herewith,the practical requirements of precipitator collecting electrodes andcertain forms of precipitator collecting electrode constitutingimprovements over electrodes previously developed are explained.Precipitator collecting electrodes, which are of sheet form, should berigid and flat and parallel to each other in order to permit of theemployment of maximum voltage in the electrostatic field creatingelectrodes without arcing across to the collecting electrodes. In saidcopending application certain forms of improved electrode are disclosedbut no electrodes or electrode units or sections designed to beinterfitted are disclosed.

It is desirable in forming a precipitator collecting electrode of largearea to make the electrode sectional, i. e., to assemble sections orunits into a composite electrode. The present invention is animprovement under the invention of said copending application and isdirected primarily to the provision of a precipitator collectingelectrode adapted to be formed by assembling sections or units. At thesame time the electrode and the sections or units comprising it conformto the requirements of a satisfactory electrode as above explained.

I provide a precipitator collecting electrode comprising a sheet offoraminous metal bent to provide a plurality of thicknesses disposed insubstantial parallelism with space between adjacent thicknesses, thethicknesses being braced against one another to form a substantiallyrigid unit. I prefer to use expanded metal in the fabrication of myprecipitator collecting electrode, flattened expanded metal being foundideal for the purpose.

Desirably a precipitator collecting electrode is formed by bending backupon itself a sheet of foraminous metal to provide two thicknessesdisposed in substantial parallelism with space therebetween, the edgesof the sheet opposite the bend being brought together and braced againstone another to form a substantially rigid unit. The edges of the sheetopposite the bend are desirably welded together. The bent edge may havean outwardly open groove for receiving an edge of another sheet orsection or unit.

I further provide a sectional precipitator collecting electrodecomprising a plurality of sections each comprising a plurality ofthicknesses of foraminous metal disposed in substantial par- 2 allelismwith space between adjacent thicknesses, the sections being interfittedat adjacent edges thereof. Each section may have at one marginal portiona relatively thin edge and at an opposite marginal portion a relativelythick edge with an outwardly open groove, the relatively thin edge ofone section being inserted into the groove of another section. Thethicknesses of metal are preferably braced against one another to form asubstantially rigid unit and' are desirably welded together at therelatively thin edge. That edge, since it comprises two thicknesses ofmetal, may be termed a double edge or a double thickness edge.

The sections or units are thus adapted to interfit to brace or reinforceone another and to cooperatively maintain the electrode as a whole fiatand rigid. Electrodes of very large size may be built up out ofprefabricated sections made as will be explained below yet each sectionmay be comparatively light in weight and easy to handle. The sectionsare very easily assembled and disassembled.

Other details, objects and advantages of the invention will becomeapparent as the following description of a present preferred embodimentthereof proceeds.

In the accompanying drawings I have shown a present preferred embodimentof the invention in which Figure 1 is a fragmentary plan view of aprecipitator collecting electrode made up of three sections or units;and

Figure 2 is an edge view of the electrode shown in Figure 1.

Referring now more particularly to the drawings, there is shown aprecipitator collecting electrode designated generally by referencenumeral 2 which comprises three sections each designated 3, each sectioncomprising two thicknesses 4 of expanded metal. In the form shown, eachsection 3 is made out of a single sheet of expanded metal bent as shownin Figure 2. The thicknesses 4 are arranged in substantial parallelism.

In making one of the sections 3, a sheet of flattened expanded metal isbent over upon itself so that the two thicknesses 4 lie in parallelismand spaced apart and the edge at the bend is further formed to providean outwardly open groove 5. At the edge of the section or unit oppositethe groove 5 the metal is bent inwardly as shown at 6 and the sheetedges 1 are brought together and braced against each other so that asubstantially rigid unit is formed. The edges 1 may be and preferablyare welded together. When a complete electrode is to be formed, sections3 are assembled by inserting the double edge portion 1 of one sectioninto the groove of another section as shown in Figure 2.

The electrode shown in the drawings is frameless. Ordinarily it is notnecessary to provide a frame around the electrode although it may beframed if desired. An advantage in not framing the electrode is thatwhen it is unframed there is less horizontal surface area to catch solidparticles falling therefrom. When the electrodes are shocked or vibratedto dislodge the particles adhering thereto it is desired that thoseparticles drop free of the electrodes. I

While any suitable foraminousmetal may be employed in making thesections 3, I desirably employ flattened expanded metal. Flattenedexpanded metal i in efiect cold worked foraminous sheet metal havingstrands and bonds forming diamonds of the shapeof the characteristicdiamonds of expanded metal. The expanded metal may be flattened bypassing it through a stand of rolls of a .cold rolling mill. Thus theelectrode is doubly strong and rigid first because the metal itself isof exceptional strength .and rigidity and second because the sectionsreinforce and strengthen each other and maintain the electrode very flatand rigid.

The sections v3 may be welded together if desired, in which case theelectrode can be suspended without any support from beneath. However, ifdesired, the sections may be simply interfitted and not welded-to eachother and the lower section may be supported in any-suitable way, theupper sections being carried by'the lower section and maintained inposition by guides such as channels at their vertical edges. When anelectrode is thus installed the grooves 5 extend horizontally. They mayalso bearranged vertically ing procedure such as resistance welding orspot welding. Since :both edges are of the same gage a sound Weld iseasily formed without inducing substantial stresses in'any part of thesection as i likely to occur when a thin metal member is welded to acomparatively heavy member.

While I have shown and described a-present preferred embodiment of theinvention, .it is to be distinctly understood that the invention is notlimited thereto but may be otherwise variously embodied within thescopeof thefollowing claims.

I claim:

1. A precipitator collecting electrode comprising a sheet of foraminousmetal bent to provide a plurality of thicknesses disposed in substantialparallelism with space between adjacent thicknesses, the thicknessesrespectively having parts removed from the bent portion of the electrodeextending toward and abutting each other whereby the thicknesses arebraced against one another-to form a substantially rigid unit.

Number 2. A precipitator collecting electrode comprising a sheet ofexpanded metal bent to provide a plurality of thicknesses disposed insubstantial parallelism with space between adjacent thicknesses, thethicknesses respectively having generally parallel flanges lying againsteach other whereby the thicknesses are braced against one another toform .a substantiallyrigid unit.

3. A precipitator collecting electrode comprising a sheet of foraminousmetal bent back upon itself .to provide two thicknesses disposed insubstantial parallelism with space therebetwecn, the edges of the sheetopposite the bend being brought together and braced against one anotherto form a substantially rigid unit, the bent edge of the unit having anoutwardly open groove for receiving an edge of another unit.

4. A sectional precipitator collecting electrode comprising a pluralityof sections each comprising a plurality of thicknesses of foraminousmetal disposed in substantial parallelism With space between adjacentthicknesses and having at one marginal portion a relatively thin edgeand at an opposite marginal portion a relatively thick edge with anoutwardly open groove, the relatively thin edge of one section beinginserted into the groove of another section.

5. A sectional precipitator collecting electrode comprising a pluralityof sections each comprising a sheet of foraminous metal bent back uponitself to provide two thicknesses disposed in substantial parallelismwith spacetherebetween, the edges of the sheet opposite the bend beingbrought together and braced against one another to form a substantiallyrigid unit, the bent edge havin an outwardly open groove, the firstmentioned edges of one section being inserted into the groove of anothersection.

6. A sectional precipitator collecting electrode comprising a pluralityof sections each comprising a sheet of flattened expanded metal bentback upon itself to provide two thicknesses disposed in substantialparallelism with space therebetween, the edges of the sheet opposite thebend being brought together and welded together to form a doublethickness edge, the bend edge having an outwardly open groove formedtherein, the double thickness edge of one section being inserted intothe groove of another section.

WAYNE E. MACK.

REFERENGES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date Arras June 24, 1930 Anderson Feb. 24.,1931 FOREIGN PATENTS Country Date Great Britain Apr. 30, 1931 GreatBritain Feb. 6, 1939 Germany Dec. 20, 1928 Germany Sept. 26, 1931 FranceDec. 23, 1930 Sweden Nov. 17,1924

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